[U-Boot] [PATCH v2 02/14] efi_loader: bootmgr: add load option helper functions

AKASHI Takahiro
2018-11-05T09:06:41Z

In this patch, helper functions for an load option variable (BootXXXX)
are added:
* efi_deserialize_load_option(): parse a string into load_option data
(renamed from parse_load_option and exported)
* efi_serialize_load_option(): convert load_option data into a string

Those functions will be used to implement efishell command.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
---
include/efi_loader.h | 23 +++++++++
lib/efi_loader/efi_bootmgr.c | 93 +++++++++++++++++++++++-------------
2 files changed, 83 insertions(+), 33 deletions(-)

diff --git a/include/efi_loader.h b/include/efi_loader.h
index 5c2485bd03e4..d83de906fbce 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -517,6 +517,29 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name, efi_guid_t *vendor,
u32 attributes, efi_uintn_t data_size,
void *data);

+/*
+ * See section 3.1.3 in the v2.7 UEFI spec for more details on
+ * the layout of EFI_LOAD_OPTION. In short it is:
+ *
+ * typedef struct _EFI_LOAD_OPTION {
+ * UINT32 Attributes;
+ * UINT16 FilePathListLength;
+ * // CHAR16 Description[]; <-- variable length, NULL terminated
+ * // EFI_DEVICE_PATH_PROTOCOL FilePathList[];
+ * <-- FilePathListLength bytes
+ * // UINT8 OptionalData[];
+ * } EFI_LOAD_OPTION;
+ */
+struct efi_load_option {
+ u32 attributes;
+ u16 file_path_length;
+ u16 *label;
+ struct efi_device_path *file_path;
+ u8 *optional_data;
+};
+
+void efi_deserialize_load_option(struct efi_load_option *lo, u8 *data);
+unsigned long efi_serialize_load_option(struct efi_load_option *lo, u8 **data);
void *efi_bootmgr_load(struct efi_device_path **device_path,
struct efi_device_path **file_path);

diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
index 2aae12e15456..a095df3f540b 100644
--- a/lib/efi_loader/efi_bootmgr.c
+++ b/lib/efi_loader/efi_bootmgr.c
@@ -9,6 +9,7 @@
#include <charset.h>
#include <malloc.h>
#include <efi_loader.h>
+#include <asm/unaligned.h>

static const struct efi_boot_services *bs;
static const struct efi_runtime_services *rs;
@@ -30,42 +31,68 @@ static const struct efi_runtime_services *rs;
*/

-/*
- * See section 3.1.3 in the v2.7 UEFI spec for more details on
- * the layout of EFI_LOAD_OPTION. In short it is:
- *
- * typedef struct _EFI_LOAD_OPTION {
- * UINT32 Attributes;
- * UINT16 FilePathListLength;
- * // CHAR16 Description[]; <-- variable length, NULL terminated
- * // EFI_DEVICE_PATH_PROTOCOL FilePathList[]; <-- FilePathListLength bytes
- * // UINT8 OptionalData[];
- * } EFI_LOAD_OPTION;
- */
-struct load_option {
- u32 attributes;
- u16 file_path_length;
- u16 *label;
- struct efi_device_path *file_path;
- u8 *optional_data;
-};
-
-/* parse an EFI_LOAD_OPTION, as described above */
-static void parse_load_option(struct load_option *lo, void *ptr)
+/* Parse serialized data and transform it into efi_load_option structure */
+void efi_deserialize_load_option(struct efi_load_option *lo, u8 *data)
{
- lo->attributes = *(u32 *)ptr;
- ptr += sizeof(u32);
+ lo->attributes = get_unaligned_le32(data);
+ data += sizeof(u32);
+
+ lo->file_path_length = get_unaligned_le16(data);
+ data += sizeof(u16);

- lo->file_path_length = *(u16 *)ptr;
- ptr += sizeof(u16);
+ /* FIXME */
+ lo->label = (u16 *)data;
+ data += (u16_strlen(lo->label) + 1) * sizeof(u16);

- lo->label = ptr;
- ptr += (u16_strlen(lo->label) + 1) * 2;
+ /* FIXME */
+ lo->file_path = (struct efi_device_path *)data;
+ data += lo->file_path_length;

- lo->file_path = ptr;
- ptr += lo->file_path_length;
+ lo->optional_data = data;
+}

- lo->optional_data = ptr;
+/*
+ * Serialize efi_load_option structure into byte stream for BootXXXX.
+ * Return a size of allocated data.
+ */
+unsigned long efi_serialize_load_option(struct efi_load_option *lo, u8 **data)
+{
+ unsigned long label_len, option_len;
+ unsigned long size;
+ u8 *p;
+
+ label_len = (u16_strlen(lo->label) + 1) * sizeof(u16);
+ option_len = strlen((char *)lo->optional_data);
+
+ /* total size */
+ size = sizeof(lo->attributes);
+ size += sizeof(lo->file_path_length);
+ size += label_len;
+ size += lo->file_path_length;
+ size += option_len + 1;
+ p = malloc(size);
+ if (!p)
+ return 0;
+
+ /* copy data */
+ *data = p;
+ memcpy(p, &lo->attributes, sizeof(lo->attributes));
+ p += sizeof(lo->attributes);
+
+ memcpy(p, &lo->file_path_length, sizeof(lo->file_path_length));
+ p += sizeof(lo->file_path_length);
+
+ memcpy(p, lo->label, label_len);
+ p += label_len;
+
+ memcpy(p, lo->file_path, lo->file_path_length);
+ p += lo->file_path_length;
+
+ memcpy(p, lo->optional_data, option_len);
+ p += option_len;
+ *(char *)p = '\0';
+
+ return size;
}

/* free() the result */
@@ -100,7 +127,7 @@ static void *get_var(u16 *name, const efi_guid_t *vendor,
static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
struct efi_device_path **file_path)
{
- struct load_option lo;
+ struct efi_load_option lo;
u16 varname[] = L"Boot0000";
u16 hexmap[] = L"0123456789ABCDEF";
void *load_option, *image = NULL;
@@ -115,7 +142,7 @@ static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
if (!load_option)
return NULL;

- parse_load_option(&lo, load_option);
+ efi_deserialize_load_option(&lo, load_option);

if (lo.attributes & LOAD_OPTION_ACTIVE) {
efi_status_t ret;
--
2.19.0